Nasu Katsuhiro, Kuroki Yoshihumi, Nawano Shigeru, Kuroki Seiko, Tsukamoto Tatsuaki, Yamamoto Seiji, Motoori Ken, Ueda Takuya
Department of Diagnostic Radiology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba 277-8577, Japan.
Radiology. 2006 Apr;239(1):122-30. doi: 10.1148/radiol.2383041384. Epub 2006 Feb 21.
To retrospectively compare accuracy of diffusion-weighted (DW) single-shot echo-planar imaging with sensitivity encoding (SENSE) with that of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging in the evaluation of hepatic metastases due to extrahepatic malignancies.
Patients provided informed consent; ethics committee approval was not required. The data of 24 patients (16 men, eight women; age range, 41-68 years; mean age, 61.9 years) with 40 resected hepatic metastases were retrospectively reviewed. Before SPIO administration, DW SENSE imaging and T2-weighted fast spin-echo (SE) and T1-weighted dual-echo fast field-echo (FFE) MR imaging were performed. After SPIO administration, T2-weighted fast SE, T1-weighted dual-echo, and T2*-weighted FFE MR examinations were performed. Images were divided into two sets: The SPIO-enhanced MR image set consisted of pre- and postcontrast T2-weighted fast SE and dual-echo T1-weighted FFE images and postcontrast T2*-weighted FFE images. The DW SENSE image set included DW SENSE images and precontrast T2-weighted fast SE and dual-echo T1-weighted FFE images. Three radiologists individually interpreted these images and sorted the confidence levels for presence of hepatic metastasis in each section into five grades. Area under the receiver operating characteristic (ROC) curve (A(z)) was calculated for each image set.
Hepatic metastases showed higher signal intensity on DW SENSE images than on T2-weighted fast SE images. Conversely, signals from vessels and cysts were suppressed with DW SENSE imaging. ROC analysis showed higher A(z) values when the DW SENSE image set was interpreted (0.90) than when the SPIO-enhanced MR image set was interpreted (0.81). The sensitivity and specificity, respectively, of total cases were 0.66 and 0.90, for the SPIO-enhanced MR image set and 0.82 and 0.94 for the DW SENSE image set. During SPIO-enhanced MR image interpretation, lesions 1 cm in diameter or smaller showed significantly lower sensitivity than lesions larger than 1 cm in diameter. During both interpretation sessions, left lobe lesions showed significantly lower sensitivity than right lobe lesions.
Combined reading of DW SENSE images and T2-weighted fast SE and dual-echo T1-weighted FFE MR images showed higher accuracy in the detection of hepatic metastases than did reading of SPIO-enhanced MR images.
回顾性比较扩散加权（DW）单次激发回波平面成像联合敏感性编码（SENSE）与超顺磁性氧化铁（SPIO）增强磁共振（MR）成像在评估肝外恶性肿瘤所致肝转移瘤中的准确性。
患者签署知情同意书；无需伦理委员会批准。回顾性分析24例（16例男性，8例女性；年龄范围41 - 68岁；平均年龄61.9岁）共40个经手术切除的肝转移瘤患者的数据。在注射SPIO之前，进行DW SENSE成像以及T2加权快速自旋回波（SE）和T1加权双回波快速场回波（FFE）MR成像。注射SPIO之后，进行T2加权快速SE、T1加权双回波以及T2加权FFE MR检查。图像分为两组：SPIO增强MR图像组包括注射对比剂前后的T2加权快速SE图像、双回波T1加权FFE图像以及注射对比剂后的T2加权FFE图像。DW SENSE图像组包括DW SENSE图像以及注射对比剂前的T2加权快速SE图像和双回波T1加权FFE图像。三位放射科医生分别解读这些图像，并将每个层面肝转移瘤存在的置信度分为五个等级。计算每个图像组的受试者操作特征（ROC）曲线下面积（A(z)）。
肝转移瘤在DW SENSE图像上的信号强度高于T2加权快速SE图像。相反，DW SENSE成像可抑制血管和囊肿的信号。ROC分析显示，解读DW SENSE图像组时的A(z)值（0.90）高于解读SPIO增强MR图像组时的A(z)值（0.81）。SPIO增强MR图像组的总病例敏感性和特异性分别为0.66和0.90，DW SENSE图像组分别为0.82和0.94。在解读SPIO增强MR图像时，直径1 cm或更小的病灶敏感性显著低于直径大于1 cm的病灶。在两次解读过程中，左叶病灶的敏感性均显著低于右叶病灶。
与解读SPIO增强MR图像相比，联合解读DW SENSE图像以及T2加权快速SE和双回波T1加权FFE MR图像在检测肝转移瘤方面具有更高的准确性。
